Ozone depleting substances

Ozone depleting substances are halogen-containing substances that damage the ozone layer in the upper atmosphere (known as the stratosphere). Some ozone depleting substances are also powerful greenhouse gases, meaning that they contribute to climate change. The most important ozone depleting substances (ODS) are:

  • Chlorofluorocarbons (CFCs)
  • Hydrochlorofluorcarbons (HCFCs)
  • Halons
  • Methyl Chloroform
  • Carbon Tetrachloride (the main precursor of CFCs)
  • Methyl Bromide

Common examples of these include refrigerants, solvents, foam blowing agents, fire fighting fluids, substances used for fumigation and soil sterilisation. CFCs, HCFCs and Halon 1301 are both ozone depleting substances and greenhouse gases.

SEPA’s role

As part of our regulatory duties, we promote and ensure compliance with the F gas and ODS Regulations that apply to industrial sites permitted under Part A of the Pollution Prevention and Control (Scotland) Regulations 2000 (as amended).

Other industrial sites, commercial and retail businesses are regulated by local authorities. Offshore oil and gas installations are regulated by The Department for Business, Enterprise and Regulatory Reform (BERR). 

A government funded team - F-Gas Support external link - provides guidance for manufacturers, operators, contractors and others that make, sell or handle F gases and ODS and associated equipment.

More on process industry regulation

What is being done?

Many ozone depleting substances are banned or are being phased out. International agreement to limit the production and consumption of ozone depleting substances was reached in 1987 through the Montreal Protocol on Substances that Deplete the Ozone Layer, which aims to reduce and eventually eliminate emissions of man-made ozone depleting substances. The protocol has been revised and amended over the years, and now contains new controls on methyl bromide, with a phase out from 1 January 2005, and a blanket exemption for quarantine and pre-shipment uses, and provision for critical uses after the phase out. The controls on HCFCs were strengthened in Vienna by introducing a 2.8% cap on consumption and phase out in 2020, with a 0.5% allowance until 2030 for servicing existing refrigeration equipment.

Industrialised countries have agreed to phase out halocarbons. Some critical uses are exempt and developing countries have been given longer time-scales. The UK did not stop CFC production until 2000. By the late 1990s, atmospheric concentrations of other halocarbons had levelled out. Bromine concentrations should peak between 2000 and 2010, but will decline only slowly because a high proportion comes from uncontrolled sources, including the oceans.

Concentrations of HCFCs have increased from the early 1990s because they are used as a substitute for CFCs. Globally, HCFCs must be cut by 99.5% by 2020 and should begin to decline after 2010 as they are phased out. HCFCs will be banned in the European Union from 2015.

Stockpiled, recycled and illegally traded CFCs, together with those in refrigeration and fire-fighting equipment, will still be around for many years. The EU has regulations external link to prevent leaks of ozone depleting substances and promote recovery after use in industrial processes, although not in manufactured products.  Information on the domestic legislation introduced in the UK can be found in the link below.

The Environmental Protection (Controls on Ozone-Depleting Substances) Regulations 2002 external link 

How does damage to the ozone layer affect the UK?

Ozone layer damage extends from the Arctic to northern Europe, including the UK. At Camborne in Cornwall and Lerwick in the Shetland Islands, total ozone concentrations have generally fallen since 1979 (suggesting ozone loss), although there has been an increase in recent years.

Declining ozone values mean ultraviolet (UV) radiation levels have increased over the UK. UV exposure stops our immune systems working properly, making us more prone to develop eye cataracts and skin cancers. Deaths in England and Wales from malignant skin melanomas rose from 200 to 300 per year in the early 1950s to 1,766 in 2003. UV radiation may also damage plants, and the young stages of aquatic wildlife.